UART simulation

h8536/emulator/uart.py

@@ -0,0 +1,35 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+
+
+@dataclass(frozen=True)
+class UartTiming:
+    baud: int = 38_400
+    data_bits: int = 8
+    parity_bits: int = 0
+    stop_bits: int = 1
+    start_bits: int = 1
+
+    @property
+    def bits_per_character(self) -> int:
+        return self.start_bits + self.data_bits + self.parity_bits + self.stop_bits
+
+    def seconds_per_character(self) -> float:
+        return self.bits_per_character / max(1, self.baud)
+
+    def micros_per_character(self) -> float:
+        return 1_000_000.0 * self.seconds_per_character()
+
+    def cycles_per_character(self, clock_hz: int) -> int:
+        return max(1, round(max(1, clock_hz) * self.seconds_per_character()))
+
+    def summary(self, clock_hz: int) -> str:
+        return (
+            f"uart_{self.data_bits}{'N' if self.parity_bits == 0 else 'P'}{self.stop_bits} "
+            f"baud={self.baud} byte_us={self.micros_per_character():.3f} "
+            f"byte_cycles={self.cycles_per_character(clock_hz)}"
+        )
+
+
+__all__ = ["UartTiming"]